The Sparkassen have discovered, that waiting to transmit the chipTAN-data via flickercode takes bloody ages at times and came up with something new and revolutionary: a QR-code!

As far as I can tell, the same data that goes into the flickercode is just put inside a QR-code for scanning convenience. Seems like there is going a little bit of encoding going into the QR-code: https://gist.gi

Need to comment in the README.md that it should be chmod'd to 0600.

Additionally we should probably encrypt it like is done within heroku/netrc.

We should use unsigned conversion when converting byte[] representation of the d number to BigInteger. See Bouncy Castle utility method:

https://github.com/bcgit/bc-java/blob/ff19d41ba1968fe381d67794d32d959aca307406/core/src/main/java/org/bouncycastle/util/BigIntegers.java#L108